The "rules" for setting brake balance?

Discussion in 'GT6 Tuning' started by SillyBillyP, Jan 2, 2014.

  1. danielc

    danielc

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    160hp 40k euros? Sell it, buy an audi s3=double hp.... And you wouldnt have to toss the brake discs after once... Lol
    And if you see the second link i sent, it compares an american, japanese and euro car in 3 sizes, sedans suvs and sports cars. The passat had its best 100-0 stop on its 12th go, while other cars were breaking 100ft further.
     
  2. stb155

    stb155

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    Was a rental, so maybe someone else did the trick before :)
    (But no vibration before and quite noticeable afterwards)
     
  3. danielc

    danielc

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    9 out of 10 times its just a bigger pad deposit in a spot of the disk (due to overheating pads) a simple grind of the pad material from disc would have made them ready for another go.
    On topic, i find the ammount of pedal to lock the disc are quite acurate, you can only stomp on it with abs/downforce or a very very nicely set up car. Whats innacurate its what happens next... You have a micro second to react and its doesnt become like ice on the road...
     
  4. Ridox2JZGTE

    Ridox2JZGTE

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    I guess I am the only one who don't have any issues with no ABS + racing brakes kit + high BB :) Using stick here - almost all of my cars have at either 9/3 BB or 9/2 BB, regardless if racing brake kit is installed or not. I actually prefer the more powerful brakes as I don't have to press harder to reach optimum braking force - as the input button I used needs considerable pressure to reach optimum braking force with standard brakes.

    That Diablo actually has racing brakes kit installed with 9/2 BB. Notice that brake force red bar only goes up to around 30-40% at most, and less than 20% on lower speed braking. The issue with pedal is how much travel to reach 30% brake force red bar on HUD ? Now if the travel is a bit longer and offers more resistance, it would be much easier :D

    The easy fix from PD is to adjust the game instead, specifically for wheel/pedal input range. Make the brake to be less sensitive, if my old worn out DS2 can perform well ( using square for brake - beats the shoulder button and right analog ), then why can't PD fine tune the pedal sensitivity, the hardware is more than capable already :D
     
  5. stb155

    stb155

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    Nice Links...

    So not much use for race brakes in GT(6) and that they made them just way stronger (they lock up way earlier if same brake pressure is applied) to give us the feeling that they are better is just wrong.

    Edit:
    Or maybe not if they (PD) mixed pedal travel with pedal force ?

    Because according to the link you have less pedal travel (due to steel flex lines and monobloc calipers) with the kit brakes, but you need more or less the same force for the same braking effect (more depending on the pads than the brakes)
     
    Last edited: Jan 2, 2014
  6. danielc

    danielc

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    The next gen wheels should have "f1 inspired" brake bias adjuster....
    But as a fix pd could introduce brake deadzone and linearity characteristics
     
  7. danielc

    danielc

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    I use a stoptech kit, designed for leaving the rest alone(master cylinder, rear brakes, etc) there is little more force required, less travel but you feel more where the pads are against the disk and you have a specific point you know its the locking edge. Also the pads i use are progressive, they increase the cf over time, wich help control. Oem pads are regressive(specially vws) they spike from the first contact but the longer you keep braking the lower the cf .
    I also drove a "custom" kit with 8 pistons all around and no math involved in doing the kit. Just because big brake.... It felt like the gt racing brakes, at the slightest touch it would lock, so maybe pd should partner with brembo/etc to polish another corner of their rough diamond.
     
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  8. HBR-Roadhog

    HBR-Roadhog

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    I took a car to the SSX track and did my testing using the meter lines on the track as a guide. I found that at 0 or 10 the stopping distance was the same with the same amount of brake applied. I tested with ABS 0 and found that if I did it just right my stopping distance was just a little bit better than with ABS 1 but only when I did it just right. I also found that 0 or 5 or 10 seemed to lock the wheels at the same amount of brake applied with racing brakes installed and RH tires any way. My test was done in the HSV AE
     
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  9. stb155

    stb155

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    This is a bit of a special case then i would say if you use only 20-30% input for you maximum braking.

    With L2, Stick or even pedal this would be a bit difficult.

    You also drive like this online ?

    I can do ok with 5/5 standard brakes on the DS3 (L2) on singleplayer, but online i often do "full panic lockups" if someone in front brake a bit early or spins. Much easier with 0/3 or something like that.
    (But i only tried it for 2-3h, so just not used to it)
     
    Last edited: Jan 2, 2014
  10. Ridox2JZGTE

    Ridox2JZGTE

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    That 20%-30% is the HUD brake bar meter on racing brakes :) It will lock at around that point, what matters most is the input device ( pedal travel vs brake force produced ) or in my case the button that I use ( I use DS2 from PS2 - a must have - the buttons are millions time better than DS3 )

    I use same setup for everything, online racing, seasonal TT, tuning/testing, arcade races - I shared one replay here :

    That Cizeta has high brake balance, 9/2, not really sure if it has racing brakes or standard brakes, you can check the replay if you want, easily identifiable when I brake from high speed ( above 250kmh, if the brake meter on the HUD is above 50%, then it's standard brakes ) The difference on the brake meter is not much, standard hovers around 30%-60%, but I often apply full force 100% for a split second from high speed :)
     
  11. stb155

    stb155

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    Yeah, i hate their brakes (on casual cars like Golf or Caddy).
    Low-resistance force in the pedal so you adjust with travel instead of pressure/feel.
    Always end up first being to careful, then pushing a bit more and having them bite to much.

    Not that bad but requires some "get used to" every time before i drive them smooth.

    But it's not only VW and not only brakes (power steering too), seems like in GT everything has to become more easy going to please the masses :yuck:
     
  12. Flying Kiwi

    Flying Kiwi

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    After reading through the masses of really useful information in this thread, I have come to a conclusion;

    PD need to apply brake fade simulation to standard brakes.
    Only then, will racing brake kits be worthy of purchasing....
     
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  13. HBR-Roadhog

    HBR-Roadhog

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    Yes and no, brake fade would make them pretty much a must have for everyone on every car that has any speed.

    There is however plenty of reason to use them for many of us. I use a wheel and club sport pedals and with standard brakes I have to apply quite a lot of force to get the car to slow down properly where with racing brakes I can apply much less force to get the same result.
     
  14. stb155

    stb155

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    So the race brakes a useless for the game and not properly simulated but they can be very useful as workaround for the not existing deadzone and sesitivity setting for input devices if you use a pedal or button that not allows you to use 100% of the available input range :idea:

    So simple, why can't PD put it in the manual :)

    Next to the thing with deteriorating body rigidity, to small rear tires and wrong steering rack on R8's
     
  15. Oshawa-Joe

    Oshawa-Joe

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    Last edited: Jan 2, 2014
  16. Griffith500

    Griffith500

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    Oh, so many cars have incorrect steering angles / ratios, it's bewildering. It's like they apply the DS3 settings to wheels as well. Luckily, I can crudely adjust the range of rotation on my wheel, but still.
     
  17. danielc

    danielc

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    For a g27 pedal i am finding it weird because there is no way to feel the lock is happening or pressure, if i could customize the linearity so that almost 100% my pedal was 65-70% game brake, maybe higher end, fanatec pedals you can taylor more , can someone chime in about that?
     
  18. Oshawa-Joe

    Oshawa-Joe

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  19. stb155

    stb155

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    On my fanatec CSR elite pedal i can adjust the sensitivity of the load cell.
    Means i can adjust how much force i have to put on the pedal to make it give 100% input to the game directly on the brake pedal.

    In GT5 i have it at max. sensitivity (low force needed) and use about 7/5 or 7/7 brake bias with race cars.
    To lock brakes up at high speed in a LMP car i still need quite a bit of pressure* to lock the front up, on low speed it is much easier.
    I have to reduce pressure as i become slower and come closer to a corner to not lock up, and that makes it feel real.
    Late braking in corners with inside wheel locked and having to release brake and hope it will turn in is such a amazing feel.

    *a lot stronger compared to normal game pedals, about equal to what i have to push in my real car in casual/city driving.

    Edit: also got clutch and brake converted to vertical as it is in most production cars.
     
    Last edited: Jan 3, 2014
  20. danielc

    danielc

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    I ve done something similar to nixim, but still, every other sim/game/ipad app/ ea crap has it... And helps consistency a lot knowing you have a physical limit. I cant watch the brake indicator to make a decision if i should press more or less my pedal... Specially with half an inch travel and .01in more means lockup
    Pd has to have linearity and deadzone, its just not available to us.
    On another note, maybe its time for a new set of pedals...
    Quick question, did anyone here tried ultimate supercars game?
     
  21. stb155

    stb155

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    Brake is good on mine.

    But i got issues with clutch, feels so wrong if you are used to the feel a real one has.
    Also you miss the clues sound and acceleration give you in a real car.
    Real hard for me to use it on start and downshifts (in a sporty/fast way)
    GT6 is very forgiving on downshift regarding lock up/loosing traction but instead drops me in N often if it is not happy with timing or revs.
    (Not so much in races but annoying in the tests&missions)

    I wish Fanatec had some gadget to simulate the feeling of getting to the grinding point.
    (Rotation damper on adjustable rack or something)

    Guess i have to get used to it.
     
  22. danielc

    danielc

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    I stopped using the clutch for the same reason, it becomes just another way to become slower/more inconsistent and pros are shadowed by the cons. Instead i removed the pedal and switchd the brake in its place for more space between pedals
     
  23. GTP_Jonjig

    GTP_Jonjig

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    I have no issues with racing brakes and 0 abs, big respect for high BB though :bowdown:..
    I use pedals and only barely touch the brake with low BB, so for me turning to high BB just increases my braking distance horrendously.. not the games fault though (same in gt5 as well) its just too sensitive for me, need to get a sponge ball behind it lol ..
     
  24. shmogt

    shmogt

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    5,812
    They should of just made brakes normal with no changes allowed and once you buy racing brakes they get a bit stronger and you can now edit them. This double edit thing is weird since stock brakes you shouldn't be able to tweak.
     
  25. NLxAROSA

    NLxAROSA Premium

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    It's how I always treated brake balance, as a relative number, so I think @jonjig is right. 5/5 on a ZR1 is not the same as 5/5 on a Leaf! 5/5 simply means 'default'. And it may very well mean that you can make a brake balance of let's say 4/6 and still be front biased!

    The theory that I and a few other tuners had is that, since (prior to GT6) you could not change the brakes, the actual bias/force is always the same (rotors/pads/wheel size). The balance is then more like a 'sensitivity' number that allows more control over how (quickly) to apply that force, so it's more of an indirect change of bias rather than a direct one.

    And then there is of course ABS, which is more like a 'physics modifier' than just plain ABS, so with ABS on it's even less straightforward.
     
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  26. BlueShift

    BlueShift

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    If you want "rules" : usually the higher is where the motor is.

    If prefer this : go on a straigth line, very @ full speed with brakes set at 10/10. Brake strong until you stop. If tires were red, decrease the brakes.
    When you found the correct numbers, -2 in front and rear and voila, you can also brake and turn.

    This, for straight line braking. Now if you want to brake in curve, do the same thing in curves and see if front or rear loose traction first and decrease the brakes there.
     
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  27. Griffith500

    Griffith500

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    It could be something like that, although "sensitivity", in my mind, is just "force amplification" anyway. It's not consistently sensible from car to car, because they're effectively different scales per axle, thanks to the "default", built-in bias. But yeah 5,5 is definitely "default" rather than an actual, effective brake bias value - if we knew the built in bias and the zero values, we could still work out the actual bias from those settings, because they are still proportional (as far as I can tell).

    As an example off the top of my head, I've been faffing with an R32 GTS25 Type S (NA tuning project; in anticipation of improved sounds), and the optimal bias I found for circuit driving is 7,10 or 6,9 depending on the track / corner - 7,10 feeling more forward and 6,9 close to the threshold of locking up the rears first (which makes sense from looking at the numbers - 6 in 9 is less than 7 in 10). That's for CS tyres; the stock brakes are obviously very "weak".

    With ABS on, though, it has no problem slowing down, but I have to use all of the brake pedal "travel" (same on any car). The moment you turn ABS off, usually the limit of braking power is much lower down in the travel (might be due to excessively forward biases in some cases). ABS is clearly doing its own thing, possibly the pedal travel being a braking power "request", whose maximum is the sum total of available grip, constantly updated from the loads available at the four corners, or something.
    The trouble is that the power is directed to the wheels individually according to their load, so the bias front/rear and left/right per axle is controlled by those loads at maximum power, but reducing the applied brake travel changes those biases according to which "channel" gets desaturated first, presumably resulting in equal distribution amongst all four wheels when each is below its limit. Quite how the bias setting fits in with that, I don't know.
    Regardless of whether the details of my assumptions there are accurate, what's obvious is that, with ABS on, the four-wheel brake biases are dependent on applied power as well as what the car is doing (and maybe also the setting). Weird.


    Anyway, the whole thing implies there are two layers to the bias setting: the stock braking forces F,R and the in-game settings f,r, which are calibrated on some scale with respective zeros of c,d, likely indeterminable. Changing the brakes changes F,R, possibly also their relation i.e. the ratio F/R, the stock bias being F/(F+R) - call that B. The in-game setting is effectively a "bias-modifier" dependent on the zeros: (f+c)/(f+c+r+d) - call that A.
    The overall bias is then O = AB = [F(f+c)] / [(F+R)(f+c+r+d)], and the effective forces at the wheels are ... in there somewhere.

    Nothing like making things simple, is there?

    PD: Please let us simply pick values of bias B and T total braking force, where the effective forces at the wheels are F,R with F = BT and R = B'T = T-F.

    Simple, intuitive and consistent! If you fit stickier tyres, just up the force accordingly, rather than juggle single-digit ratios until you find a bias close to what you had before. The brake upgrades should primarily be for fade resistance, since the extra torque from larger rotors can be compensated with a smaller applied force (meaning the same applied pedal pressure for "maximum effort").
    They finally caved in with the aero settings, now for the brake bias! :gtpflag:
     
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  28. BlueShift

    BlueShift

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    a- That's why in a standard tune, front > rear is generally a good idea on FR/FF.

    The brake are set for standard weigth.

    Say a car weigth is 1200kg, with 300 kg of engine. Put it to 1000kg. The engine is still 300kg... I'm not sure the front:rear weigth distribution gets updated while removing weigth aswell.

    b- Anyway, we could put equations everywhere, I think testing is what makes a difference between a tuner and an excell sheet. The excell sheet can tell you how the car is supposed to brake, accel, hold the curve, but it have few things about weigth transfert...

    In a curve, one single tire can support 65% of the car if not more + kinetic energy.

    c- ABS irl works like the game LSD, on both tires. I always wondered if ABS, regardless of you braking or not, had an effect on Initial/Accel/Decel amounts of power given to the "not spinning tire". I also wonder if these are the same units.

    Units for LSD are % of slip allowed
    if I remember well.
     
    Last edited: Jan 5, 2014
  29. Griffith500

    Griffith500

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    The "formulas" are to illustrate the unnecessary complexity PD have introduced for what ought to be a simple tuning aspect. The brake bias numbers in the game do not represent an actual bias (in the main), so in fact you can have the front < rear in the setting sheet but still have a forward bias on the car, regardless of dynamic weight transfer (7,10 on the Skyline I mentioned is a forward bias on an FR car with no weight reduction, yet - it locks the fronts first).

    ABS does indeed affect LSD operation in the real world; that is, it complicates it by messing with the distribution of engine braking torque, causing interactions that are hard to tune for. The analogue in acceleration would be separate in-wheel motors and an ordinary engine driving the diff on the same axle.
    I don't know that ABS can properly be called equivalent to an LSD, although the electronic clutch types come closest in operation - both are forms of "traction control", of course.

    Diffs can be described as having a "bias ratio", too (which can be converted to percentage slip with some "formulas", depending on the type of diff); e.g. if, say, a helical diff has a 2:1 bias, twice the torque of the "spinning" wheel will be sent to the non-spinning wheel. That works out at about 35% "locking", apparently, as the total useful torque transfer is still limited by the spinning wheel. Some diffs, e.g. viscous couplings, don't have static biases. Bias is a useful number if your goal is torque vectoring, like an Evo or GTR etc.
     
  30. danielc

    danielc

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    All the gizmos regarding traction and stability controls irl are additional abs functions...
    Xds, from vw simulates a diff breaking the proper individual wheel(it doesnt feel as good as a lsd and is reactive vs proactive)
    And newer torque vectoring functions as well
    Also abs would work like a diff entering a corner because it would reduce brake pressure in the inner wheel due to weight transfer taking weight off that wheel